Kitchen appliance and system therefor

ABSTRACT

A kitchen appliance has a control arrangement arranged to receive sound commands and to operate the appliance in response to the sound commands; a microphone arranged to receive sound comprising a sound command and to provide the sound to the control arrangement; and at least one acoustic filter configured to suppress from the sound provided to the control arrangement background noise created by operation of the kitchen appliance.

The present invention relates to a kitchen appliance, such as anappliance for processing food or a beverage making appliance, and forcontrol by means of sound commands, in particular to so-called“artificially intelligent” kitchen appliances. The present inventionalso relates to a system for controlling a kitchen appliance.

Current kitchen appliances are often unhygienic, as a user is requiredmanually to push buttons/screens or turn rotary switches to control themachine. In food preparation this can lead to food contamination. Forexample, the user may have put raw chicken in their cooking kitchenmachine and turned the machine on. A few hours later they may forgetthat they have done this, and again turn the machine on. This can resultin a spread of bacteria, which is capable of causing the user (or otherusers) to become ill.

Furthermore, current kitchen appliances have fixed outcomes. All currentmachines behave in the same way regardless of, for example, the context,country or culture they are being used in. For example, the eatinghabits of someone living in France compared to someone living in SouthAmerica can vary significantly, therefore a smart appliance which canrecognise the individual and learn to suggest the recipes that fit theirdiet is unique.

According to the invention, there is provided a kitchen appliance suchas a food processing appliance having a control arrangement arranged toreceive sound commands and to operate the appliance in response to thesound commands, a microphone arranged to receive sound comprising asound command and to provide the sound to the control arrangement; andat least one acoustic filter configured to suppress from the soundprovided to the control arrangement background noise created byoperation of the food processing appliance.

Thus the invention may enable or enhance the ability of a foodprocessing appliance to be operated by sound commands such as voicecontrol, even when the appliance is operating.

“Background noise” may herein be used to connote any sound other thanthe sound command, in particular sound that is disruptive to thedetection of the sound command.

The acoustic filter may be further configured to suppress backgroundnoise from any other source. “Sound command” may herein be used toconnote any sound that conveys a predetermined meaning, such asinformation, a question or an instruction. Preferably, the term “soundcommand” encompasses, at least a voice command.

Preferably the acoustic filter is arranged to suppress noise created bymovement of moving parts of the food processing appliance. For example,the food processing appliance may comprises a motor for driving a foodprocessing tool, and the acoustic filter may be arranged to suppressnoise created by operation of the motor.

Preferably the motor is one selected from the group comprising brushlessmotors and reluctance motors as these are quiet, accuratelycontrollable, and do not generate brush-dust. More preferably the motoris one of a switched or a synchronous reluctance motor.

Preferably, the food processing appliance comprises a sensor for sensingat least one of: speed; torque; current; rotor-position; and directionof the motor, and the acoustic filter may be configured to vary thesuppression of background noise in dependence on the sensor output. Theacoustic filter may be adapted to vary any of the magnitude andfrequency range of the suppression. Moreover the microphone may besensitive to sound between 20 Hz to 20 kHz, more preferably soundbetween 200 Hz to 4 kHz, and still more preferably to sound between 400Hz and 2.5 kHz.

The sensor may be one selected from the group comprising opticalencoders, magnetic encoders, hall-effect sensors, and sensors detectingcharacteristics of electrical current flowing through the motor withprocessing means for calculating speed and/or torque of the motor basedon the detected characteristic.

The acoustic filter may be configured to suppress background noisebefore and/or after a sound is detected by the microphone, and maycomprise an active and/or passive noise cancellation system. Theacoustic filter may comprise: an analogue signal filter, a digitalsignal filter, a high pass filter, a bandpass filter, and/or a popscreen.

Preferably, the food processing appliance comprises a processor arrangedto identify an operating instruction from a sound command. For example,the instruction may be a command to: operate and/or adapt functionalityof the food processing appliance and/or of any peripheral device withwhich it is in communication; operate the food processing appliance,including activate/deactivate a predetermined program for the foodprocessing appliance and change operation of the food processingappliance (including, for example, processing temperature, time and/orspeed); and/or save, retrieve, communicate and/or output information(including a recommendation).

Preferably, the microphone comprises a liquid-tight cover, and theacoustic filter may comprise the cover.

The food processing appliance may be a stand mixer, blender, foodprocessor, juicer or mincer.

The invention also provides a system for controlling a food processingappliance that is operable by means of sound commands, the systemcomprising: a microphone; a processor for processing sound from themicrophone so as to identify an instruction from the sound command; anda food processing appliance comprising a controller configured toreceive the instruction from the processor and to control the foodprocessing appliance in dependence on the instruction, wherein at leastone of the microphone and the processor is arranged as part of a deviceother than the food processing appliance, for example a mobilecommunication device or a smart speaker.

Preferably the device other than the food processing appliance is inwireless communication with the microphone and/or food processingappliance, and more preferably by means of BlueTooth® and/or WiFi.Preferably, the microphone and the processor are both in the foodprocessing appliance or are both in the same device other than the foodprocessing appliance. Preferably, the microphone is in a handheld mobilecommunication device and the processor is part of a cloud computingnetwork.

Optionally the system further comprises a distance and/or orientationsensor for determining the distance and/or orientation of a sound-sourcerelative to the microphone, and may also comprise an acoustic filterconfigured to vary suppression of sound from a source in dependence onthe distance and/or orientation of the sound-source detected by thedistance and/or orientation sensor. In this way noise sources comingfrom a specific distance, orientation and/or direction can besuppressed, or alternatively all sound not coming from a given source(e.g., the user) may be suppressed.

Preferably the system further comprises a memory in which the detecteddistance and/or orientation of a sound-source can be stored. This avoidsthe need for repeated processing. More preferably still where sound isnot detected from that sound source for a predetermined amount of time,say 24 hours, the data is deleted to free up memory.

The food processing appliance may comprise a transceiver, preferably forwireless communication with the processor and/or microphone. Theprocessor is preferably configured to identify a quality relating to thesound command, and to determine the instruction from the quality that isidentified.

The quality may be a meaning, sentiment or mood that is associated withthe way in which a sound is expressed, for example its speed, pitch,cadence and volume, as well as any emphasis and intonation (and thevariation of any of these exemplary aspects).

The invention also provides a system for controlling a kitchen appliancesuch as a food processing appliance that is operable by means of soundcommands, the system comprising: a microphone; a processor forprocessing sound from the microphone so as to identify from the sound asound command and a quality relating to the sound command, and toprovide an instruction in dependence upon the command and the quality;and a food processing appliance comprising a controller configured toreceive the instruction from the processor and to control the foodprocessing appliance in dependence on the instruction.

The processor may be configured for speech recognition, for examplecomprising an API for speech recognition. The processor may covert soundcommands into text, and may convert text derived from the sound commandinto the instruction.

The sound command may be in the form of a voice command from a user, andthe quality may be the identity of the user, and the controller may bearranged to control the food processing appliance in dependence on theidentified user.

Preferably the system comprises a database for storing data relating toidentified users and/or relating to various food processing applianceswhich may be controlled by the system, wherein the processor isconfigured to retrieve, from the database, data relating to a given useror appliance once the user or appliance has been identified. Preferably,the data stored in the database comprises user preferences include,including at least one of: user interface settings and food preferencesand patterns. Preferably, the food processing appliance and/or theprocessor are/is in communication with the database so as to retrieveand store user preferences from and to the database.

In one example, the controller is configured to control the foodprocessing appliance in dependence on at least one of: time of day;ambient light levels; and weather.

Preferably the controller is configured to control the food processingappliance so as to output information, preferably the informationrelating to a proposed food processing operation, such as arecommendation for a recipe or an ingredient.

The processor may be configured to identify an instruction based onmachine learning, preferably the instruction being the output ofinformation relating to a proposed operation. Preferably, the machinelearning is trained from previous actions by a given user or a group ofusers. Previous actions are stored on the database.

Preferably, the group of users are a plurality of users other than agiven user, and more preferably the group of users is a subset of allusers wherein the subset comprises similar characteristics to a givenuser. The characteristics may include any of: age; location; sex;physical characteristics; family membership, position, or status;desired diet; culture; ethnicity; marital status; occupation;personality; culinary preferences; and allergies.

The microphone is optionally activated by a device other than the foodprocessing appliance, such as a proximity sensor; a camera; amicrophone; and/or a button. The microphone may be activated at ascheduled time, or may be constantly activated.

Preferably, the food processing appliance comprises a wirelesstransceiver for communicating with the processor and/or microphone.

The system may comprise a food processing appliance as defined above.

The invention also provides a food processing appliance for processingfood comprising: a microphone, wherein the food processing appliance iscontrolled in dependence on signals received by the microphone; and aliquid-tight cover at least partially shielding the microphone fromfood. Thus the microphone may be protected from spillage.

Preferably, the cover is formed from a low-friction, hydrophobic and/oroleophobic material, and may be shaped to allow food to slide off of thecover, for example with steep faces or orientated to allow food to slideoff of the cover, for example with downwardly-orientated face.

Preferably, the microphone is provided proximate to where food isprocessed in the food processing appliance, and more preferably within15 cm, and still more preferably within 10 cm or 5 cm.

The invention also encompasses a kit of parts for constructing any ofthe apparatuses or apparatus elements herein described.

Any apparatus feature as described herein may also be provided as amethod feature, and vice versa. As used herein, means plus functionfeatures may be expressed alternatively in terms of their correspondingstructure, such as a suitably programmed processor and associatedmemory.

Any feature in one aspect of the invention may be applied to otheraspects of the invention, in any appropriate combination. In particular,method aspects may be applied to apparatus aspects, and vice versa.Furthermore, any, some and/or all features in one aspect can be appliedto any, some and/or all features in any other aspect, in any appropriatecombination.

It should also be appreciated that particular combinations of thevarious features described and defined in any aspects of the inventioncan be implemented and/or supplied and/or used independently.

In this specification the word ‘or’ can be interpreted in the exclusiveor inclusive sense unless stated otherwise.

Furthermore, features implemented in hardware may generally beimplemented in software, and vice versa. Any reference to software andhardware features herein should be construed accordingly.

Whilst the invention has been described in the field of domestic foodprocessing and preparation machines, it can also be implemented in anyfield of use where efficient, effective and convenient preparationand/or processing of material is desired, either on an industrial scaleand/or in small amounts. The field of use includes the preparationand/or processing of: chemicals; pharmaceuticals; paints; buildingmaterials; clothing materials; agricultural and/or veterinary feedsand/or treatments, including fertilisers, grain and other agriculturaland/or veterinary products; oils; fuels; dyes; cosmetics; plastics;tars; finishes; waxes; varnishes; beverages; medical and/or biologicalresearch materials; solders; alloys; effluent; and/or other substances,and any reference to “food” herein may be replaced by such workingmediums. It will be appreciated that the processing of food may includethe processing and/or blending of liquid, and may also include theprocessing of solid food or ice into a liquid form.

Whilst the invention has been described in terms of a kitchen appliance,any device from the fields in the preceding paragraph may alsoprofitably incorporate the invention described herein. Any voice-controlor speech-reception/transmission mechanism associated with anelectrically-powered vehicle or electrically-powered machinery mayprofitably incorporate the noise-cancellation dependent onmotor-speed/characteristics, or any other advantageous feature describedherein. However, this invention is considered particularly advantageousin the kitchen field for the reasons described herein.

The invention described here may be used in any kitchen appliance and/oras a stand-alone device. This includes any domestic food-processingand/or preparation machine, including both top-driven machines (e.g.stand-mixers) and bottom-driven machines (e.g. blenders). It may beimplemented in heated and/or cooled machines. It may be used in amachine that is built-in to a work-top or work surface, or in astand-alone device. The invention can also be provided as a stand-alonedevice, whether motor-driven or manually powered.

The invention described herein may also be applied to beverage-makingmachines. For example, fully-automatic coffee machines (e.g. due to thenoise generated by their grinders), kettles (e.g. due to the soundemitted whilst boiling), drip coffee machines (e.g. due to the soundcreated by the steam-bubbles used to drive water) can all profit fromenhanced noise cancellation. The term “kitchen appliance” should beinterpreted as including beverage-makers as well as food processingappliances.

Embodiments will now be described, by way of example only and withreference to the accompanying drawings having like-reference numerals,in which:

FIG. 1 show schematic diagrams of systems for controlling a kitchenappliance for processing food by means of a voice command;

FIG. 2 is a schematic diagram of an acoustic filter system in a kitchenappliance for processing food by means of a voice command;

FIG. 3 is a flow diagram of a process of controlling a kitchen appliancefor processing food by means of a voice command; and

FIG. 4 illustrates a process for activating a microphone in a system forcontrolling a kitchen appliance for processing food by means of a voicecommand.

SPECIFIC DESCRIPTION

FIG. 1a illustrates a system for controlling a kitchen appliance 100 forprocessing food (i.e. a food processing appliance) by means of a voicecommand. The kitchen appliance is, for example, a stand mixer, blender,grinder, juicer, or the like.

The kitchen appliance 100 comprises: an input for receiving an audiosignal 110; a control arrangement (or processor, such as a centralprocessing unit) for processing an input audio signal 120; and acontroller 130 for controlling the kitchen appliance in dependence on(the input audio signal that is processed by) the processor. The audiosignal may be associated with a voice command from a user 140.

In one example, the input 110 is a microphone. The microphone istriggered to start input of sound for recognition by the processor 120.Input sound is then sent to an Application Programming Interface (API)for recognition and speech-to-text analysis by the processor 120, and anASCII string of the input sound is output. The ASCII string is thenprocessed, by the processor, using natural language processing, whichfor example identifies keywords from the string such as “actions” (e.g.programs, length of time, etc.). The actions from the string are theninterpreted as instructions that are used to control the kitchenappliance, to provide feedback or to suggest recipes and/or functions.

For example, the microphone 110 records the sound input “prepare a cakemix”, which is forwarded to the processor 120. The processor, by meansof speech recognition, identifies the intention of the voice command andassociates this with an appropriate instruction (e.g. from a library ofcommands), for example to activate (by means of the control circuitry130) a mixing programme for cake mixture, which defines the type of toolto be used, mixing times and/or speeds. In addition, the processorinstructs the controller to communicate to the user at least one recipefor a cake.

Alternatively, the input 110 is an audio input jack (e.g. for receivingan audio signal from an external device).

The library of commands used may be a library selected from a group oflibraries based on meta-data sent with the forwarded sound-inputindicating that the input is associated with a specific user, group ofusers, appliance, or group of appliances. This library may be apre-constructed one, or one built up through repeated user interactionsusing e.g., machine learning, or a mixture of the two.

The microphone 110 is preferably provided proximate to where food isprocessed in the food processing appliance 100, and more preferablywithin 15 cm, and still more preferably within 10 cm or 5 cm. Thisensures that the user may speak directly to it, and it is close enoughto pick up the user's voice with relative clarity.

In an alternative example shown in FIG. 1b , the input 110 is a datatransfer and/or internet connectivity unit (e.g. BlueTooth® or Wi-Fiunit) that is capable of receiving data (such as a command and/or arecipe) directly from a speech recognition unit 140.

The speech recognition unit 140 is a peripheral communication device(not shown) that is capable of receiving sound and speech recognition(either by itself or via communication with a networked entity, such aswithin a cloud network). The speech recognition unit 140 comprises,either as part of the peripheral communication device or as part of thenetworked entity, a database comprising: recipes; food recommendations;user identifiers (including voice identifiers); a library or librariesof instructions for use with appliances which may be downloaded from aserver via the internet when the speech recognition unit 140 isconnected to the appliance 100, or the speech recognition unit 140 maydirectly query the library or libraries on the server when receivinginstructions; and/or user preferences.

The input 110 (and thus kitchen appliance 100) and the speechrecognition unit 140 are configured to communicate bi-directionally. Inthis way, the speech recognition unit 140 can receive diagnosticinformation regarding the kitchen appliance and/or users' details(including users' identities and preferences). Feedback may thus beprovided to the user from the appliance 100 either directly from aninterface of the appliance 100 or via the speech recognition unit 140.

In order to operate the kitchen appliance 100 by means of a voicecommand, the user provides a voice command to the speech recognitionunit 140 (e.g. directly to the peripheral communication device), whichprocesses (either locally or distantly at the networked entity) thevoice command as outlined in relation to FIG. 1 a.

A command is received by the input 110, which is forwarded to theCentral Processing Unit 120 and control circuitry 130 in order to affectthe operation of the kitchen appliance and/or to communicate to the usera recipe or recommendation.

In one example, the speech recognition unit 140 comprises a peripheralcommunication device in the form of a mobile phone, a tablet or apersonal computer. However the speech recognition unit 140 may be anydevice in electronic communication (wired or wireless, direct ormediated through one or more intermediaries) with the kitchen appliance100. For example, the speech recognition unit 140 may be a stand-alonemicrophone assembly (optionally including a speaker for providingauditory feedback to the user) such as an Amazon Echo™ or Google Home™smart-speaker or other such smart-speaker. Spoken instructions for theappliance 100 may be enabled on the smart-speaker through activation ona cloud-based online profile by, e.g., purchasing a software applicationon the cloud-based service on which the profile resides.

FIG. 1c is yet another example of a system for controlling a kitchenappliance 100 for processing food by means of a voice command.

FIG. 2 shows the use of an acoustic filter to improve sound input so asto control a kitchen appliance.

When the input 110 is in the form of a microphone (or sound input moregenerally) incorporated in the kitchen appliance 100, in order for themicrophone accurately to detect sound, without distortion or disruption,the kitchen appliance 100 comprises an acoustic filter configured tosuppress background noise. A contributor to background noise mightinclude the noise of the motor and/or other moving parts of the kitchenappliance, such as the contact of a tool of the kitchen appliance withfood and with a bowl of the kitchen appliance.

A sound 200, which includes a voice command, is input into the kitchenappliance via the microphone 110. In one example, the microphonecomprises an acoustic filter 210. For example, the acoustic filterutilises passive noise cancellation (such as sound insulation, vibrationisolation, a pop screen and/or a windscreen) and/or active noisecancellation.

The active noise cancellation operates by sensing (e.g. by means of asecond microphone, not shown) sound from a noise source (such as noise232 from the motor 230), either by emitting (for example by means of aspeaker, not shown) sound that destructively interferes with thedetected noise or by other means for cancelling noise from soundreceived by any of the microphones.

In addition or alternatively, the processor 120 of the kitchenappliance, which receives an audio input from the microphone 110, alsocomprises (or is in communication with) an acoustic filter 220. Theacoustic filter 220 is in the form of an analogue or digital filter,such as a low-pass or bandpass filter.

When the motor 230 of the kitchen appliance is running, the acousticfilter(s) (210 and/or 220) is used (once activated, where appropriate)so as to eliminate some, if not all, background noise (i.e. that whichdoes not form part of the voice command) prior to processing of theaudio input by the processor 120 (sand/or the speech recognition unit140).

The kitchen appliance further comprises a motor sensor 240 for sensingthe speed, torque, rotor-position, or other characteristic of the motor,from which frequency, pitch, intensity, and amplitude of sound emittedby the motor is predicted in order to aid the acoustic filters (210and/or 220) to reduce noise by adapting the operation of the filter(s),for example by removing noise for the switching components that controlthe speed of the motor.

The motor 230 may be a brushless motor for reducing noise caused bybrushes sweeping across electrical contacts within the motor 230, aswell as reducing the creation of brush-dust that may contaminate food.In one example, the motor 230 may be a reluctance motor such as asynchronous or switched reluctance motor, which allow accurate controlof motor characteristics like rotor-position (i.e., the angular positionof a given point on the rotor relative to its central axis). The motorsensor 240 may be an optical encoder, magnetic encoder, hall-effectsensor detecting a magnetic encoder, or may consist of a sensordetecting characteristics of electrical current flowing through themotor and suitable processing means for calculatingspeed/torque/position of the motor based on the feedback of this sensor.

The microphone(s) 110 that is (/are) incorporated within the kitchenappliance may be exposed to food, including liquids and small particles.As a result, in order to improve longevity of microphone, the microphoneis provided with a cover (not shown) that is configured to shield themicrophone from food.

Where the microphone 110 is located outside the kitchen appliance 100(e.g., in a phone, tablet, or other mobile device), it may include orcommunicate with a location sensor for determining its location,distance, and/or orientation relative to the appliance 100 and/or itsmotor 230. Feedback from this sensor may then be used to determine anappropriate level or characteristic of noise-cancellation, for exampleby cancelling sound arriving at the microphone corresponding to soundemanating from the distance and/or orientation of the appliance 100.

The location sensor may be a simple range-determining sensor usingelectro-magnetic transmissions (including light, infra-red, andradio-frequency) from one of the microphone 110 and appliance 100 to theother of the microphone 110 and appliance 100. Alternatively thelocation sensor may comprise global positioning system (GPS)terminal(s), or indoor positioning system (IPS) modules using visual,inertial or other data to determine the position (either in absoluteterms, or relative) of both the microphone 110 and the appliance 100 andthus their relative distance. Orientation of the microphone 110 may bedetermined by sensing using either a magnetic compass and/or agravitational sensor, or by other known means.

One draw-back of determining distance only is that this does not accountfor the acoustic path between the microphone 110 and the appliance 100being potentially longer than the absolute distance due to, for example,sound bouncing around a corner. One possible way of compensating forthis is to use known details of the location in which the microphone issituated to compensate for this (e.g., a house-plan downloaded from asuitable database, or information collected via a visual sensor andproceed using image-recognition software) by determining the acousticpath. Another way is to use an array of microphones, such as a far-fieldarray (FFA) to triangulate the orientation and distance of the appliance(or at least the orientation of sound from the appliance arriving at theFFA and its acoustic path-length) relative to the microphone 110.

In an alternative or additional implementation, the distance (eitherdirect or acoustic) and/or orientation of the user is determined usingsimilar techniques to those above, and all other sound (i.e., fromsources at differing distances) is suppressed/cancelled.

Preferably the location/distance sensor is associated with a memory inwhich the location and/or distance of a sound-source can be stored. Eachsound source may be identified with a relatively easy-to-determineidentifier (e.g., the frequency emitted). In this way repeatedprocessing to identify the distance, location, and/or orientation of asound-source for cancellation purposes may be avoided. Where noise hasnot been detected from the stored sound-source for a predeterminedtime-period (e.g., 24 hours) it may be deleted from the memory.

For example, the cover is a waterproof enclosure, such as a rubber boot.The cover is shaped to allow food to slide off of the cover. The boot isalso orientated to allow food to slide off, such that liquids/food thatmay spill down the machine do not fall and block the microphone. Thecover is preferably formed from, or coated with, a low-friction,hydrophobic and/or oleophobic material (such as PTFE) to preventmaterial sticking to it and to repel watery/oily food materials.

In order better to interpret voice command, the kitchen appliance isconfigured to interpret a quality relating to the sound command, such asa “mood” (i.e. “mood recognition”) of a voice command; this process isoutlined in the flow diagram in FIG. 3. As used herein, the term “speechrecognition”, preferably, also encompasses “mood recognition”.

Sound 200 is received 300 and processed 310 as outlined above withreference to FIGS. 1 and/or 2.

At a next step 320, once the sound has been processed, the processor 120or speech recognition unit 140 (which further comprises a “moodanalyser”) analyses, for example, the pitch, inflection and/or spectralcontent of the audio signal to determine the mood of the input audiosignal, and therefore that of the user.

If a mood of the audio signal is determined (e.g. by means of artificialintelligence and/or a predefined library), operation of the kitchenappliance is adjusted at a next step based on the determined mood. Forexample, the kitchen appliance recommends a recipe based on mood 330.

The kitchen appliance therefore utilises mood analysis to become anintelligent coach. For example, identifiable moods, and correspondingrecipe suggestions, might include recipes comprising:

-   -   chocolate and/or sugar for users that sound upset (e.g.        chocolate mousse);    -   caffeine and/or food high in carbohydrates for users who sound        tired; and    -   surprise and/or novelty ingredients/recipes for users that sound        excited; and    -   healthy ingredients/“superfoods” for users that sound ill (e.g.        congested).

By means of machine learning, the kitchen appliance (and/or the speechrecognition unit 140) learns to understand the user based on the recipesthat they cook, with a consideration of, for example: the time of day;mood analysis; what nutrients a user is lacking (or has in excess); andingredients that they have available; and/or ingredients they enjoy ordislike. This will allow the user to develop a unique recipe coach andsuggestion engine.

FIG. 4 shows a process for activating the kitchen appliance in order toready the appliance for receiving a voice command.

The kitchen machine is connected to a peripheral communication device404 (such as that which forms part of the speech recognition unit 140),by means of, for example, a wireless technology, such as Bluetooth orWi-Fi. Activation of the kitchen appliance 100 is triggered by theperipheral communication device 404.

For example, in a first step 400, an application located on theperipheral communication device 404 (shown in the form of a smartphone)uses a proximity sensor on the device 410, which waits until it has beencovered (e.g. by a hand or other object) for a pre-determined period oftime by a user. Once covered for this pre-determined period of time, ina next step 420, the device listens and records sound so as to capture avoice command. The recorded sound is then analysed and converted totext—either by the device, by other parts of the speech recognition unit140, an external server to which the device 404 is connected via theinternet (such as a cloud-based speech recognition service), or by thekitchen appliance (the recorded sound having been transmitted to thekitchen appliance).

The text is received by the kitchen appliance 430 or by other parts ofthe speech recognition unit 140 (for example, if processed by thesmartphone, then via Bluetooth or Wi-Fi). Alternatively the text may bereceived by a cloud-based text recognition service and then translatedinto an identifier (for example a command-number or code) that is thentransmitted to the kitchen appliance 430. The kitchen machine or theother parts of the speech recognition unit 140 (e.g. a cloud networkentity) processes the incoming text string to see if it is a command. Ifa command is recognised, the command is communicated to the kitchenappliance, and specifically to the control circuitry 130 of the kitchenappliance.

As shown, an example of a command is the instruction to open the head ofthe kitchen appliance (where the kitchen appliance is a stand mixer, forexample), in which case the kitchen appliance will, by means of itscontrol circuitry, open the head.

Other examples of commands include: to turn the kitchen applianceon/off; to control temperature; and to control speed and heating elementtemperature settings.

Available commands (i.e., commands that the user may use at a giventime) may be displayed to user via a visual display, with commands notavailable at that time (i.e., because they are associated withfunctionalities that cannot be carried out due to the condition of theappliance at that moment) not displayed to the user. The visual displaymay be one integrated with the kitchen appliance for providing feedback,or integrated with a mobile communications device in electroniccommunication (either wireless or wired, direct or mediated through oneor more intermediaries) with the kitchen appliance 100 such as thatcomprising the speech recognition unit 140. Alternatively, or inaddition to this, the available commands may be given to the userthrough auditory feedback from a speech-capable digital assistant suchas Amazon Alexa™ or Google Assistant™ via a smart-speaker. The sets ofcommands that may be used with a given kitchen appliance 100 may beautomatically downloaded from an external server onto the device inwhich the microphone 110 or speech recognition unit 140 is integrated,or other suitable device, for communication to the user.

The microphone 110 and/or speech recognition unit 140 (anything done byone may be done by the other) may be sensitive to sound between 20 Hz to20 kHz (i.e., the approximate auditory range of a human being), morepreferably sound between 200 Hz to 4 kHz (the approximate auditory rangewithin most speech falls—also known as “voice frequency”), and stillmore preferably to sound between 400 Hz and 2.5 kHz (a frequency bandsufficient to capture enough detail to recognise speech). Using morenarrow frequency-band microphones is desirable as they are typicallycheaper, and additionally the transmission and storage of speechcaptured within a narrower frequency is easier as it includes less data.Moreover narrower-bandwidth microphones will detect less in the way ofextraneous sound.

In one alternative, any form of sound command can replace the voicecommand that is, including sound originating other than directly from ahuman; for example, this includes from pets, environmental sounds (e.g.front door closing), or from a speech synthesiser.

It will be understood that the present invention has been describedabove purely by way of example, and modifications of detail can be madewithin the scope of the invention.

Each feature disclosed in the description, and (where appropriate) theclaims and drawings may be provided independently or in any appropriatecombination.

Reference numerals appearing in the claims are by way of illustrationonly and shall have no limiting effect on the scope of the claims.

1.-38. (canceled)
 39. A kitchen appliance having: a control arrangementarranged to receive sound commands and to operate the appliance inresponse to the sound commands; a microphone arranged to receive soundcomprising a sound command and to provide the sound to the controlarrangement; and at least one acoustic filter configured to suppressfrom the sound provided to the control arrangement background noisecreated by operation of the kitchen appliance.
 40. The kitchen applianceaccording to claim 39, wherein the acoustic filter is arranged tosuppress noise created by movement of moving parts of the kitchenappliance, and/or wherein the kitchen appliance comprises a motor fordriving a food processing tool, and wherein the acoustic filter isarranged to suppress noise created by operation of the motor.
 41. Thekitchen appliance according to claim 40, wherein the motor is oneselected from the group comprising brushless motors and reluctancemotors, preferably wherein the motor is one of a switched or asynchronous reluctance motor.
 42. The kitchen appliance according toclaim 39, wherein the acoustic filter is configured to suppressbackground noise before and/or after a sound is detected by themicrophone.
 43. The kitchen appliance according to claim 39, wherein theacoustic filter is an active and/or passive noise cancellation system,and wherein the acoustic filter preferably comprises: an analogue signalfilter, a digital signal filter, a high pass filter, a bandpass filter,and/or a pop screen.
 44. The kitchen appliance according to claim 39,further comprising: a processor arranged to identify an operatinginstruction from a sound command.
 45. The kitchen appliance according toclaim 40, further comprising a sensor for sensing at least one of:speed; torque; current; and direction of the motor, and, wherein theacoustic filter is configured to vary the suppression of backgroundnoise in dependence on the sensor output.
 46. The kitchen applianceaccording to claim 45, wherein the sensor is one selected from the groupcomprising: optical encoders, magnetic encoders, hall-effect sensors,and current sensors arranged to detect characteristics of electricalcurrent flowing through the motor and having processing means forcalculating speed and/or torque of the motor based on the detectedcharacteristic.
 47. The kitchen appliance according to claim 39, whereinthe microphone is sensitive to sound between 20 Hz to 20 kHz, morepreferably sound between 200 Hz to 4 kHz, and still more preferably tosound between 400 Hz and 2.5 kHz.
 48. The kitchen appliance according toclaim 39, wherein the microphone, and preferably the acoustic filter,comprises a liquid-tight cover, preferably wherein the cover is formedof or coated with a low-friction, hydrophobic and/or oleophobicmaterial, preferably PTFE.
 49. The kitchen appliance according to claim39, wherein the kitchen appliance is a food processing appliance and/ora stand mixer, blender, food processor, juicer or mincer.
 50. Thekitchen appliance of claim 39, wherein the microphone is providedproximate to a location where food is processed in the kitchenappliance, and preferably within 15 cm, and more preferably within 10 cmor 5 cm of the location.
 51. A system for controlling the kitchenappliance of claim
 39. 52. A system for controlling a kitchen appliancethat is operable by means of sound commands, the system comprising: amicrophone; a processor for processing sound from the microphone so asto identify an instruction from the sound command; and a kitchenappliance comprising a controller configured to receive the instructionfrom the processor and to control the kitchen appliance in dependence onthe instruction, wherein at least one of the microphone and theprocessor is arranged as part of a device other than the kitchenappliance, for example a mobile communication device or a smart-speaker.53. A system for controlling a kitchen appliance that is operable bymeans of sound commands, the system comprising: a microphone; aprocessor for processing sound from the microphone so as to identifyfrom the sound a sound command and a quality relating to the soundcommand, and to provide an instruction in dependence upon the commandand the quality; and a kitchen appliance comprising a controllerconfigured to receive the instruction from the processor and to controlthe kitchen appliance in dependence on the instruction.
 54. The systemaccording to claim 53, wherein the processor is configured for speechrecognition, preferably where the sound command is in the form of avoice command from a user, and wherein the quality is the identity ofthe user, and the controller is arranged to control the kitchenappliance in dependence on the identified user, optionally furthercomprising a database for storing data relating to identified users orappliances, wherein the processor is configured to retrieve, from thedatabase, data relating to a given user or appliance once the user orappliance has been identified.
 55. The system according to claim 53,wherein the controller is configured to control the kitchen appliance independence on at least one of: time of day; ambient light levels; andweather, and/or wherein the controller is configured to control thekitchen appliance so as to output information, preferably theinformation relating to a proposed food processing operation, andoptionally wherein the processor is configured to identify aninstruction based on machine learning, preferably the instruction beingthe output of information relating to a proposed operation.
 56. Thesystem according to claim 53, wherein the microphone is activated by adevice other than the kitchen appliance, and/or wherein the kitchenappliance comprises a wireless transceiver for communicating with theprocessor and/or microphone.
 57. The system according to claim 53,wherein the kitchen appliance is defined according to claim
 39. 58. Thesystem according to claim 57, further comprising a memory configured forstoring a location and/or distance of a source of sound for use in noisecancellation, and preferably further configured to delete a storedlocation and/or orientation of a sound source if sound has not beendetected from that sound source for a predetermined time, preferably 24hours.